In my opinion it's going to look like a flag , (white ,red blue. )If you want to paint house blue go darker and maybe French blue or greyish blue it's a bit more elegant and all the trims white but be careful outside all the colours look much brighter and lighter so when think it's just right go a shade darker .

Personally I'd use Manor Red. Probably won't see a lot of it anyway so if theres a discrepancy between Colorbond and tile it won't be as obvious. I'd also guess that the Manor Red would be a darker red than the terracotta tile? Could use Basalt for gutters and facias if you want a bit of grey perhaps?

Think of introducing a contrast to the white - black being very contrasting, white not being a contrast and soft grey being somewhere in between (but possibly not quite enough, in which case you may need to go for darker shades of grey) . The analogy might be framing a picture or piece of art- If the canvas is really white, you wouldn't choose a white frame. Or putting on eye makeup- if you choose to put a colour on your lids and don't include eyeliner or mascara, your eyes will lack definition ! What colour is the roof ? Also ,have you chosen the white of the exterior yet because these two factors can help in your decision process.

No worries, Emma. I envy anyone who can picture an outcome from a 5x4cm colour swatch. I can’t. I need a bigger, more realistic visual clue. We’ve been through the same mind changes with selections too, including whether to render or not. We were fearful of creating lifelong work, fixing potential cracks in the render and repainting. In the end, we decided to leave it alone, and have an unassuming (or even deceptive) street look that makes everyone go ‘wow’ when they walk through the door because inside is not what they expected from the outside. We’ll see how the house dates in the years to come and re-visit the idea of rendering at that time. But like you, my main prob is the colour of the window frames. I’ve spray painted some internal frames. They look heaps better. Just gotta get motivated to do some more!